FileNameFormat

FileNameFormat.js

(function ($) {

    $.fn.formatfilename = function (options) {

        var settings = $.extend({
            'length': '40'
        }, options);

        return this.each(function () {
            var $this = $(this);
            var text = $.trim($this.text());
            if (text.length >= settings.length) {
                var ext = (function () {
                    var loc = text.lastIndexOf(".");
                    if (loc) {
                        var ext = text.substring(loc, text.length);
                        text = text.substring(0, loc);
                        return ext;
                    }
                    else {
                        return "";
                    }
                })();
                text = text.substring(0, settings.length-ext.length) + ext;

            }
            $this.text(text);
        });

    };
})(jQuery);

$("body").append($("<span>blah.txt</span>").formatfilename({length:6})); // bl.txt